Such pumps are known that typically include an atomizer which is activated in translatory motion in a body via a push button in a fluid dispensing and suction stroke respectively. Furthermore, to enable the liquid to be pressurised, a plunger is mounted on the atomizer so as to offer, depending on said pressure, a state where a dispensing path is blocked and a state where it is open.
To enable the system to be switched reversibly into these two states, two implementations are known from the prior art:
attaching the plunger to the atomizer, with switching from one state to the other being implemented by elastic deformation of said plunger;
mounting the plunger to slide on the atomizer and elastically constraining the movement of the one relative to the other, with switching from one state to the other then being dependent on the resultant of the constraints exerted by the constraint means and by the pressure respectively on the liquid.
In known embodiments, the plunger and the atomizer are mounted coaxially in a rigid way, typically by providing a contact zone of significant axial dimension, so as to guarantee coaxial movement of the atomizer-plunger assembly. However, these embodiments have the drawback of taking up space, which may prove restrictive when it comes to the implementation of pumps of reduced axial dimension.
Furthermore, the atomizer-plunger assembly is held coaxially in the body via a sealed support on two zones spaced apart axially, formed between the atomizer and a member secured to the body, and between the plunger and the inside of the body respectively. Consequently, the reliability of this holding arrangement and therefore of the tightness are conditioned by the spacing between the support zones, in other words by the axial dimension of the pump.